1. Field of the Invention
The present invention relates to a fault diagnosing system and method for a coolant switching device for a vehicle that prevents damage to an on-board charger (OBC) when the coolant switching device fails and coolant is not supplied to the on-board charger.
2. Background of the Related Art
Environmentally friendly vehicles such as an electric vehicle or a plug-in hybrid vehicle, are equipped with an on-board charger which slowly charges a vehicle battery using electricity of about 110V or 220V. Since the on-board charger is an electronic device, it generates a substantial amount of heat when charging the vehicle battery with electricity which is input externally. When the heat is not controlled and dissipated, the performance and life span of the on-board charger, as well as the vehicle battery decrease. Therefore, coolant is passed through the on-board charger to control and dissipate the heat which is generated during charging of the vehicle battery, and to maintain the temperature below a predetermine temperature.
A coolant pipe line which passes through the on-board charger branches off a heating water pipe line connected to a heating device which is used to heat interior air of a vehicle. A coolant switching device is disposed at the branching point which causes the coolant to flow toward the heating device or toward the on-board charger. When the coolant switching device fails, the coolant may only flow toward the heating device and the temperature of the on-board charger may not be controlled due to the failure and therefore, the on-board charger may be damaged.
Conventionally, electric vehicles do not include equipment that determines whether the coolant switching device has failed. Accordingly, a risk exists that a driver may not notice a failure of the on-board charger.
The foregoing is intended merely to aid in the understanding of the background of the present invention, and is not intended to mean that the present invention falls within the purview of the related art that is already known to those skilled in the art.